Automobiles increasingly incorporate electronic devices into the cabin. These electronic devices may include for example mobile devices, navigation systems, control systems, and/or audio/video systems. It is desirable to allow interaction with these devices using voice commands in order to allow a driver to focus on driving the automobile.
In order to allow interaction and control of electronics using voice commands using audio from an audio environment such as an automobile cabin, it is necessary to process audio signals in order to identify desired voice commands. Voice recognition is used to translate received audio into a voice command, which can then be executed to interact with or control the electronics of the automobile or devices connected thereto. However, in an automobile environment it can be difficult to isolate audio associated with a human speaker from other noise present in the cabin or external to the cabin. Additional audio that may make voice recognition difficult may include, for example, conversations from other occupants, road noise, wind noise, windshield washer noises, turn signals, etc.
Attempts to enhance audio corresponding to a specific occupant and suppress audio associated with noise have been limited in success. Some attempts use a fixed array of microphones to determine the location of an audio signal. In particular, these attempted solutions have used a phase difference between signals of individual microphones of the microphone array. Often these solutions require that the microphones in the microphone array be positioned in a specific location, with a predetermined separation between microphones. This places an undesirable restriction on automobile manufacturers when designing an automobiles interior cabin.
It would be desirable to be able to suppress off-axis audio in an audio environment while allowing flexibility in the position of microphones.